526 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
photograph of the type specimen (plate 3, figure 1) shows the large open primary 
panicle, like that of the type of P. expansum, which is characteristic of the early 
phase of the species. 
DESCRIPTION. 
Plants perennial in tangled masses; culms slender, subcompressed, a line of pubes- 
cence down one side or glabrous, rarely sparsely pilose, straggling, widely creeping, 
rooting at the lower nodes, as much as 2 meters long, freely branching, the branches 
usually divergent, becoming nearly as long as the 
primary culm; nodes puberulent or glabrate; sheaths 
much shorter than the usually elongate internodes, 
sparsely papillose-pilose or papillose only, densely 
ciliate on the margin, puberulent at the junction with 
the blade; ligule about 0.3 mm. long; blades thin, 
flat, spreading, 5 to 10 cm. (rarely as much as 15 
em.) long, 5 to 10 mm. wide, narrowly lanceolate, 
acuminate, rounded and usually ciliate at base, scab- 
erulous on both surfaces at least on the midnerve, 
: usually papillose-hispid above the ligule, sometimes 
Fig, 135.—P, cordovense. From — gharsely so throughout; panicles of two kinds, the 
Ticheock $328. primary short-exserted or included at base, loose and 
open, 10 <o 15 cm. long, half to two-thirds as wide, the axis and branches slender, sub- 
flexuous, scaberulous, pubescent in the axils,the few branches solitary or in pairs, 
remote, simple or nearly s0, finally spreading, few-flowered, the branchlets and short- 
pediceled, apparently unfruitful spikelets more or less appressed to the rachis, the 
secondary panicles terminal on the branches, 
reduced, narrow, few-flowered, partially 
inclosed in the sheath, the crowded appar- 
ently cleistogamous spikelets fruitful; spike- 
lets 3 to 3.5 mm. long, 1.2 to 1.4 mm. wide, 
those of the primary panicles usually glab- 
rous, those of the secondary panicles usually 
pustulose-villous, turgid; first glume about 
two-thirds as long as the spikelet, obtuse, 
3 to 5-nerved, the second glume and sterile 
lemma equal, covering the fruit, 7-nerved, 
the middle internerves of the sterile lemma 
in the pubescent spikelets usually glab- 
rous, the midnerve sometimes indistinct; fruit 2.8 to 2.9 mm. long, 1.1 to 1.2 mm. 
wide, apiculate. 
The spikelets shown in figures 135 and 136 are from the terminal and lateral panicles 
respectively of the same individual. 
Fig. 136.—P. cordovense. From Hitchcock 8328, 
DISTRIBUTION. 
Shady banks and in deep woods, southern Mexico to Argentina. 
a H mf | iy = Veracruz: Cordoba, Schaffner 293. 
Jalapa, Pringle 9208, Hitchcock 
er Me 6611. Huitmalco, Lnebmann 
Sih _ Oe, 426. 
Sea y =~ : Costa Rica: Piedra del Convento, 
aos ae ae aed Pittier 3655. 
Panama: Chiriqui Volcano, Hitch- 
{ cock 8196. El Boquete, Hitch- 
cock 8271, 8275, 8303, 8328. 
Fig. 137.—Distribution of P. cordovense. 
